Container closure



Dec. 14, 1965 A. P. ZUNDEL 3,223,277

CONTAINER CLOSURE Filed Dec. 10, 1963 2 Sheets-Sheet 1 fMWM Dec. 14, 1965 A. P. ZUNDEL 3,223,277

CONTAINER CLOSURE Filed Dec. 10 1963 2 Sheets-Sheet 2 I i /z BYQJMQM United States Patent 3,223,277 CONTAINER CLOSURE Arthur Philip Zundel, Cary, Ill., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed Dec. 10, 1963, Ser. No. 329,449 15 Claims. (Cl. 220-53) This is a continuation-in-part of my copending application Serial Number 259,583 filed February 19, 1963.

The present invention relates to an end closure for a container and in particular to such a closure which is readily openable manually, needing no special tools.

In an effort to provide the consuming public with greater conveniences there has been a marked trend in the container industry towards cans which may be easily opened using the hands alone. There is felt to be a special need for such easy-open cans for the packaging of beer and carbonated soft drinks since these types of beverages are very often consumed away from home such as on picnics and at ball games where special opening tools may not be available,

To be commercially practical an easy-open closure for a container must be relatively simple and inexpensive to manufacture since the container to which it is to be applied is to be used once and thrown away; it must be sufficiently strong to withstand any handling abuse and resist any tendency to premature opening such as due to the internal pressure within a carbonated beverage can, but at the same time be readily openable by hand; it must be and remain air-tight and liquid-tight until purposely opened and it must in no way adversely affect the packed product or be adversely affected by the product. Further, the closure must be so constructed as to minimize if not obviate any hazards to the safety of the ultimate opener and user of the container, i.e. the consumer.

It is therefore an object of the instant invention to provide an end closure for a container which is readily openable by hand without the need for special tools.

It is also an object to provide an end closure of the character described meeting the requirements set forth above.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

The above objects are accomplished by hermetically securing a plug in an aperture or opening in a container end, a portion of which plug is scored so as to be readily removable by a simple manual manipulation.

Referring to the drawing:

FIG. 1 is a plan view of an end closure embodying the instant invention;

FIG. 2 is an enlarged sectional view taken substantially along line 2-2 of FIG. 1;

FIG. 3 is an enlarged fragmentary sectional view taken substantially along line 33 of FiG. 1;

FIG. 4 is a plan view of the end closure with parts broken away;

FIG. 5 is a plan view of a modified form of the end closure;

FIG. 6 is a sectional view taken substantially along line 6-6 of FIG. 5; and

FIG. 7 is an enlarged, fragmentary view partly in section.

As one exemplary embodiment of the instant invention there is shown in FIG. 1 a sheet metal end closure generally designated 10. The end closure 10 has a substantially flat circular panel 12;, a substantially U-shaped annular reinforcing head 14 (FIG. 2) surrounding the panel 12 which head at its end remote from the panel 12 merges with an annular, outwardly extending cover book 16 for securing the closure to a container body such as in a doubleseam. The head 14- is to provide the end with buckle strength; but other end profiles may be used to provide this strength. Further, where buckle strength is not an essential requirement for the closure, such as the packaging of fruit juices, a reinforcing element in the closure such as bead 14 may be dispensed with entirely.

The portion of the closure including the panel 12, head 14 and cover hook 16 is preferably formed from tin plate. Further, this portion of the closure need not necessarily be circular but may have other configurations such as square, obround, etc.

The panel 12 along a diameter thereof but spaced from the center thereof has an aperture or opening 13. The aperture 18 may be of any substantially regular shape such as circular or polygonal; but it is preferred that the aperture 18 be generally rectangular in shape; i.e. having opposed parallel sides, with appreciably rounded corners and with the long axis of the rectangle coinciding with the panel diameter. It has been found that such a configuration is best for the firm securement of the plug, more fully described hereinafter, in the aperture 13.

The panel 12 contiguous the short side of the aperture 18 close to the center of the panel has a substantially strai ht sided notch 2% (FIG. 4). The purpose of this notch will be described more fully hereinafter.

Sealingly engaged to the panel 12 surrounding the aperture 18 and closing this aperture is a one-piece, sheet metal plug generally designated 22 having the same general configuration or shape as the aperture 18. Because of its relative tearability and corrosion resistance, the plug 22 is preferably formed from sheet aluminum. The plug 22 has a peripheral flange 24 contiguous with and overlying the portion of the panel 12 surrounding the aperture 18. A pull tab 26 extends along the diameter of the panel 12 from the short side of the plug 22 adjacent the center of the panel 12. To provide improved purchase for grasping and pulling, the pull tab has a series of corrugations 28.

A peripheral wall 30 extends laterally from the inner edge of the fiange 24 through the aperture 18 and merges with an imperforate end wall 32 extending across and sub stantially closing the aperture 18. To mechanically lock the plug to the panel 12 the peripheral wall 30 is collapsed around its entire periphery except for the portion 31 which merges with the pull tab 26. When so collapsed, the portion of the panel 12 surrounding the aperture 18, except for that adjacent wall portion 31, is crimped or n tight frictional engagement between the flange 24 and the underlying portion of the wall 39.

It has been found that the notch 2i prevents the wall portion 31 from collapsing as does the remainder of the Wall 39. The beading and collapsing operation also reorients the wall portion 31 from a vertical disposition to a downwardly sloping disposition away from the pull tab 26 toward the center of the plug. The uncollapsed condition of the wall portion 31 has been found necessary to permit consistent easy removal of a tear out area 33 of the plug, described more fully hereinafter; and the sloping disposition of the wall portion 31 has been found to facilitate greatly this easy and consistent removal of the tear out area 33.

To insure a hermetic liquid-tight seal between the plug 22 and panel 12 a synthetic resin sealant 34 adheres to and covers the periphery of the plug end wall 32 and adjacent surface of the panel 12 on what will eventually be the inside of the end closure 10. The sealant 34-, applied as a liquid to the clinched-in plug and subsequently hardened, fiows into any interstices between the plug 22 and panel 12 thereby completely closing and sealing the aperture 18.

If desired, the sealant 34 may be applied to the plug 22, such as at the juncture of the wall 30 and flange 24, before the plug is inserted in the aperture 18. After the clinching operation, the sealant so applied is contained between the layers of clinched metal thereby providing a hermetic seal between the plug and panel. It is also within the purview of the instant invention to apply the sealant 34 by a combination of those means described above, i.e. sealant being applied to the plug 22 both before and after its assembly with the panel 12. Following this last mentioned procedure, sealant may be applied to selected portions of the plug prior to assembly and to the remaining portions of the plug after its assembly with the panel.

The sealant 34 may be of any suitable type which is non-toxic since it is exposed on the inside surface of the closure 10. Examples of suitable compositions for the sealant 34 are plastisols such as those described in US. Patent $16,002,641, hot melt polyamide adhesives such as disclosed in US. Patent #2,840,264, and rubber base sealing compositions of the type disclosed in US. Patent #2,767,152.

The side edges of the pull tab 26 adjacent the flange 24 are freed from integral conection with the flange 24 by notches 36 (FIG. 1) and are tapered inwardly to narrow this portion of the pull tab. The notches 36 extend at least partially down the adjacent, uncollapsed wall 31 and join a pair of score lines 38 which extend across the face of the end wall 32. The score lines 33 are joined at their ends remote from the notches 36 by an arcuate score line 40 thereby defining with the pull tab 26 the removal or tearout area 33 in the plug 22. By the narrowing mentioned above, the wall portion 31 which is uncollapsed and the Width of the notch 20 are minimized thereby not only maximizing the area of mechanical securement of the plug 22 to the panel 12 but also minimizing the resistance to removal of the tear-out area 33. It is to be understood that the tear-out area 33 can have any desired configuration, the substantially tear-drop shaped area shown in the drawings being merely for illustration.

T open a container having the subject closure secured to an end thereof, the tab 26 is raised from its horizontal position to an elevated position by inserting the tip of the finger or fingernail thereunder; thereafter the tab is grasped at the corrugations 28, preferably between thumb and forefinger, and pulled back along the long axis of the plug 22. The notches enable the tab 26 to be readily freed from the panel 12 with-out any tendency to bind on the flange 24 which might cause breaking of the tab. Upon continued pulling of the tab 26, the plug tears along the score lines 30 and 40 with little effort due to the relative softness of the aluminum and the absence of any crimp in the wall portion 31. This tearing continues until the tab and the area 33 Within the scored lines are completely separated from the remainder of the plug thereby providing a dispensing opening in the closure 11).

The modified form of the invention shown in FIGS. through 7 is essentially similar to the embodiment hereinbefore described but differing in a few but important aspects. Instead of having the notch 20, substantially centrally located in the short side of the aperture 18, the panel 12 is angled downwardly at 42 out of the plane of the remainder of the panel toward the plane of the imperforate end wall 32. The width of this downwardly angled portion 42 is substantially equal to the width of the pull tab 26 at its inner end where it joins the end wall 32, which pull tab inner end slopingly conforms to and is contiguous this angled portion 42.

As with the previously described embodiment, the inner free end of the pull tab 26 must not be crimped or collapsed as is the remainder of the lateral or peripheral Wall St} in order to permit easy rupturing of the end wall 32 upon pulling of the pull tab 26 with a minimal possibility of breaking the connection of the pull tab With the end wall. It has been found that the sealant 34 can more readily and more consistently effect a hermetic seal in the area 4 where the pull tab joins the end wall when the angled portion 42 is used rather than the notch 20.

Immediately adjacent the juncture of the pull tab 26 with the end Wall 32 there is provided in the end wall 32 a rib or debossment 44. It has been found that the presence of the debossment 44 greatly increases the ease of opening of the subject closure and essentially eliminates failures of these closures due either to leakers or breakage of the tab 26 where it joins the end wall 32. While not wishing to be bound by any particular theory, it is believed that the debossment 44 provides a reservoir or gathering spot for the excess metal at and around the connected end of the pull tab 26, thereby eliminating or at least reducing, any undesirable stresses in this portion of the plug 22 which might cause tab breakage. This excess metal results from the fact that there is no collapsed wall at the inner end of the tab 26. It is also believed that the debossment 44 increases the rigidity of the end wall 32 adjacent its connection to the tab 26 thereby facilitating initial rupturing of the score lines; and to this end the debossment 44, although in the most part extending transversely of the end wall 32, has appreciable width in a direction longitudinal of the end wall 32.

Extending from each side edge of the pull tab 26 in and generally longitudinal of the end wall 32, are score lines 46. The score lines extend across the debossment 44 then diverge from each other rather sharply to the sides of the end wall contiguous the collapsed wall 30; and then continue parallel to one another along the sides of the end wall 32 to the outer short side of the plug 22 adjacent the cover hook 16. The ends of the score lines 46 are joined by a score line 48 extending therebetween along the short side of the plug 22 and is also disposed in the end wall 32 adjacent the collapsed wall 30. By so locating the score lines 46, 48 for the most part around the periphery of the end wall 32 adjacent the collapsed wall 30, the collapsed wall 30 tends to cover and sheath the raw metal edge remaining after the area within the score lines has been torn out. Such sheathing of these raw edges protects any body part of the ultimate user of the can from accidental cuts.

As an additional safety feature over the embodiment previously described, at least the major portion if not all of the peripheral edges of the pull tab 26 are provided with a hem 50. The hem 50 is formed by folding over the peripheral margins of the pull tab 26 to obviate in the hemmed portion the presence of readily accessible sharp edges having any tendency to cut.

To open a container having secured to an end thereof the end closures of the instant embodiment, exactly the same procedure would be followed as has been described for the previous embodiment.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. An end closure for a tubular can body comprising:

a substantially flat panel;

an aperture in said panel; and

a one-piece thin metal plug sealingly engaged with the portion of said panel surrounding said aperture to close said aperture;

said plug comprising:

a pull tab extending away from said aperture in sub- .stantial parallelism with said panel;

an imperforate end wall extending across said aperture and substantially closing the same;

a pair of score lines extending from the innermost side edges of said tab and continuing at least partially across said end wall; and

a rib in said end wall adjacent the juncture of said score lines and said tab side edges extending across said score lines whereby upon manual lifting and pulling of said tab the portion of said end wall defined by said score lines is torn out providing a dispensing opening in said closure.

2. The closure set forth in claim 1 wherein the major portion of each of said score lines is located closely adjacent the engagement of said plug with said panel.

3. The closure set forth in claim 1 wherein the peripheral edges of said pull tab are hemmed.

4. The closure set forth in claim 1 wherein the portion of said panel contiguous the juncture of said score lines and said tab side edges is depressed below the plane in which said panel substantially lies.

5. The end closure set forth in claim 4 having additionally a sealant surrounding said aperture contiguous said peripheral wall to hermetically seal said plug in said aperture.

6. An end closure for a tubular can body comprising:

a substantially flat panel;

an aperture in said panel; and

a one piece thin metal plug sealingly engaged with the portion of said panel surrounding said aperture to close said aperture;

said plug comprising:

a flange engaging said panel on one side thereof;

a lateral wall extending angularly from said flange through said aperture and merging with an imperforate end wall disposed on the other side of said panel from said flange in substantial parallelism with said panel and extending across said aperture and substantially closing the same;

said lateral Wall being collapsed to provide, with said flange, a substantially U-shaped channel in which is engaged said panel to mechanically lock said plug in said aperture;

a pull tab integral with said end wall at one side thereof and extending away from said aperture in substantial parallelism with said panel on the same side of said panel as said flange with at least a portion of the peripheral edges of said tab being hemmed to reduce any cutting tendency thereof;

a pair of spaced score lines each extending from a side edge of said tab substantially longitudinally across said end wall and disposed for the most part adjacent a portion of said collapsed lateral Wall, and a score line extending transversely across said end wall adjacent another portion of said collapsed lateral wall to connect the ends of said pair of score lines remote from said tab, the disposition of said score lines adapted to reduce the exposure of any raw metal edge after rupture of said score lines;

a debossment in said end wall extending across said pair of score lines adjacent their juncture with said tab side edges to rigidity the end wall in the vicinity of said debossment;

the tab portion and contiguous panel portion adjacent said debossment sloping from the plane in which said flange substantially lies toward the plane in which said end wall substantially lies; and

a ring of a substantially solid synthetic resin sealant surrounding said aperture contiguous said collapsed lateral wall on the side of said panel opposite said flange to hermetically seal said plug in said aperture.

7 An end closure for a tubular can body comprising a substantially flat panel; an aperture in said panel; and a one-piece thin metal plug crimped onto and sealingly engaged with the portion of said panel surrounding said aperture to close said aperture; said plug comprising a pull tab extending from one side of said aperture in substantial parallelism with said panel, an imperforate end wall extending across said aperture and substantially closing the same, and a pair of score lines extending from the innermost side edges of said tab and continuing at least partial ly across said end wall whereby upon manual lifting and pulling of said tab the portion of said end wall defined by said score lines is separated from said end wall providing a dispensing opening in said closure.

8. The end closure set forth in claim 7 wherein said panel is sheet metal.

9. The end closure set forth in claim 8 wherein said panel is tin plate and said plug is aluminum.

lit. An end closure for a tubular can body comprising:

a substantially flat panel;

an aperture in said panel; and

a one-piece thin metal plug sealingly engaged with the portion of said panel surrounding said aperture to close said aperture;

said plug comprising:

a pull tab extending away from said aperture on one side of said panel in substantial parallelism with said panel;

an imperforate end wall extending across said aperture and substantially closing the same;

a flange engaging said panel on said one side thereof;

a. peripheral wall extending from said flange through said aperture and merging with said end wall;

said end Wall being disposed on the other side of said panel in substantial parallelism therewith;

said peripheral wall being collapsed around the greater portion of its periphery to provide a substantially U-shaped channel between said flange and said end Wall in which is engaged said portion of said panel to crimp said plug in said aperture whereby upon manual lifting and pulling of said tab the portion of said end wall defined by said score lines is separated from said end wall to provide a dispensing opening in said closure.

11. An end closure for a tubular can body comprising:

a substantially flat panel;

an aperture in said panel; and

a one-piece thin metal plug sealingly engaged with a portion of said panel surrounding said aperture to close said aperture;

said plug comprising:

a pull tab extending away from said aperture in substantial parallelism with said panel;

an imperforate end wall extending across said aperture and substantially closing the same; and

a pair of score lines extending from the innermost side edges of said tab across said end wall and joined at their ends remote from said tab whereby upon manual lifting and pulling of said tab the portion of said end Wall defined by said score lines is completely separated from said end wall to provide a dispensing opening in said closure.

12. The end closure set forth in claim 10 having additionally a sealant surrounding said aperture contiguous said peripheral wall to hermetically seal said plug in said aperture.

13. The end closure set forth in claim 10 wherein said pull tab extends from a portion of said peripheral wall and is substantially coplanar with said flange.

14. The end closure set forth in claim 13 wherein said peripheral wall portion from which said pull tab extends is uncollapsed.

15. The end closure set forth in claim 14 wherein said portion of said panel surrounding said aperture is notched adjacent said uncollapsed portion of said peripheral Wall.

References Cited by the Examiner UNITED STATES PATENTS 2,147,004 2/ 1939 Wark et al. 22053 3,059,808 10/ 1962 Clair 220-54 3,079,031 2/ 1963 Henchert 22027 3,151,766 10/1964 I-lenchert 220-54 THERON E. CONDON, Primary Examiner. 

1. AN END CLOSURE FOR A TUBULAR CAN BODY COMPRISING: A SUBSTANTIALLY FLAT PANEL; AN APERTURE IN SAID PANEL; AND A ONE-PIECE THIN METAL PLUG SEALINGLY ENGAGED WIHT THE PORTION OF SAID PANEL SURROUNDING SAID APERTURE TO CLOSE SAID APERTURE; SAID PLUG COMPRISING: A PULL TAB EXTENDING AWAY FROM SAID APERTURE IN SUBSTANTIAL PARALLELISM WITH SAID PANEL; AN IMPERFORATE END WALL EXTENDING ACROSS SAID APERTURE AND SUBSTANTIALLY CLOSING THE SAME; A PAIR OF SCORE LINES EXTENDING FROM THE INNERMOST SIDE EDGES OF SAID TAB AND CONTINUING AT LEAST PARTIALLY ACROSS SAID END WALL; AND A RIB IN SAID END WALL ADJACENT THE JUNCTURE OF SAID SCORE LINES AND SAID TAB SIDE EDGES EXTENDING ACROSS SAID SCORE LINES WHEREBY UPON MANUAL LIFTING AND PULLING OF SAID TAB THE PORTION OF SAID END WALL DEFINED BY SAID SCORE LINES IN TORN OUT PROVIDING A DISPENSING OPENING IN SAID CLOSURE. 